乌鳢致病嗜水气单胞菌的分离与毒力基因检测及耐药分析  

Isolation,Identification and Drugs Susceptibility Test of the PathogenicA eromonas hydrophila from Channa argus

作　　者：赵林辉 田佳鑫[1,2,3,4] 孔祎頔 李莹 康元环[1] 单晓枫[1] 王桂芹[1,2,3,4] ZHAO Linhui;TIAN Jiaxin;KONG Yidi;LI Ying;KANG Yuanhuan;SHAN Xiaofeng;WANG Guiqin(College of Animal Science and Technology,Jilin Agricultural University,Changchun 130118,China;Joint Laboratory of Modern Agricultural Technology International Cooperation,Ministry of Education,Changchun 130118,China;Ministry of Education Laboratory of Animal Production and Quality Security,Changchun 130118,China;Jilin Provincial Key Laboratory of Animal Nu-trition and Feed Science,Changchun 130118,China)

机构地区：[1]吉林农业大学动物科学技术学院,长春130118 [2]吉林农业大学现代农业技术教育部国际合作联合试验室,长春130118 [3]吉林农业大学动物生产及产品质量安全教育部重点试验室,长春130118 [4]吉林省动物营养与饲料科学重点实验室,长春130118

出　　处：《经济动物学报》2022年第1期52-61,共10页Journal of Economic Animal

基　　金：国家现代农业(特色淡水鱼)产业技术体系建设专项资金资助项目(CARS-46);国家自然科学基金资助项目(31372540)。

摘　　要：为鉴定南方某水产养殖基地因肠道肠炎及腹水致死乌鳢的致病菌,从患病乌鳢组织中分离得到一株优势菌株,经人工感染试验鉴定该病菌有较强的致病性,能致乌鳢、小鼠及斑马鱼患病死亡,进行形态学、理化特性分析,初步判定该菌隶属于气单胞菌属。进一步采用分子生物学方法,进行16S rDNA和管家基因序列测序,系统发育树分析,并对该菌的耐药性及毒力基因携带情况进行分析。结果表明:在16S rDNA及管家基因系统发育树上,该菌与嗜水气单胞菌聚类,且同源性高达99.1%。毒力基因检测出该W12菌株含有黏附素(aha)、丝氨酸蛋白酶(Ser)、脂肪酶(Lip)、细胞毒性肠毒素(act)、气溶素(aer)、核酸酶(exu)及密度感应系统调控基因(LuxS)7种毒力因子。细菌载量试验结果表明:在血液中亦能检测到细菌,表明该株A.hydrophia能导致菌血症,致病力较强;同时在肝脏和肾脏中细菌载量最高,其可能是细菌的主要攻击器官。药敏试验结果表明:该菌对头孢氨苄、头孢呋辛、头孢噻吩、呋喃妥因、诺氟沙星、氨苄西林、多西环素及青霉素8种药物高度敏感。毒力基因以及脏器细菌载量试验为后续药物治疗提供有效靶点,药敏试验为生产应用中的快速治疗提供科学依据。In order to identify the pathogenic bacteria causing the death of snakehead(Channa argus) due to enteritis and ascites in an aquaculture base in southern China, a dominant strain was isolated from the tissues of diseased snakehead(Channa argus). According to the analysis of morphology and physicochemical characteristics, it was preliminarily determined that the strain belonged to Aeromonas. Furthermore, 16 S rDNA and housekeeping gene sequences were sequenced, phylogenetic tree was analyzed, and the drug resistance and virulence genes were analyzed. The results showed that the strain was clustered with Aeromonas hydrophila based on the phylogenetic tree of 16 S rDNA and housekeeping gene, and the homology was as high as 99.1%. Seven virulence factors including Ser, Lip, act, aer, exu, and LuxS were detected in the strain of W12. The results of bacterial load test showed that the bacteria could also be detected in blood to indicate that A.hydrophia could cause bacteremia, which meaned that the bacteria had strong pathogenicity. Meanwhile, the bacterial load was the highest in liver and kidney, which might be the main attacking organs of bacteria. The results of drug sensitivity test showed that the strain was highly sensitive to cefalexin, cefuroxime, cefotaxin, nitrofurantoin, norfloxacin, ampicillin, doxycycline and penicillin. Virulence genes and organ bacterial load test provide effective targets for follow-up drug treatment, and drug sensitivity test provides scientific basis for rapid treatment for production and application.

关 键 词：嗜水气单胞菌 乌鳢 耐药性 理化特性 毒力基因 

分 类 号：S941.429[农业科学—水产养殖]